看到 Leecode 的题目，发现 python 的数据结构，但是工作中目前没有用到链表这个结构，尴尬

#-*- coding: utf-8 -*-
# Definition for singly-linked list.
class ListNode(object):
    def __init__(self, x, Node=None):
        self.val = x
        self.next = Node

    def __repr__(self):
        '''
        用来定义Node的字符输出，
        print为输出data
        '''
        return str(self.val)


class Chain(object):
    def __init__(self,head=None,length=0):
        self.head = head
        self.length = length

    def isEmpty(self):
        return (self.length == 0)

    def appendNode(self,dataOrNode):#在末尾增加一个节点
        item = None
        if  isinstance(item,ListNode):
            item = dataOrNode
        else:
            item = ListNode(dataOrNode)

        if  not self.head:
            self.head = item
            self.length += 1

        else:
            node = self.head
            while node.next: #遍历到最后一个节点
                node = node.next
            node.next = item
            self.length += 1

    def deleteNode(self,index):
        if self.isEmpty():
            print "this chain table is empty."
            return
        if index <0 or  index >= self.length:
            print 'error: out of index'
            return

        if  index == 0:
            self.head = self.head.next
            self.length -= 1
            return

        #遍历到该index，记录这个index节点的前一个跟后一个

        #将前一个节点的next 指向下个节点就Over
        #pre_node 记录index的前一个节点，node记录当前节点
        start = 0##第一个节点位置
        pre_node = self.head
        node = self.head
        while node.next and start < index:
            pre_node = node
            node = pre_node.next
            start += 1
        if  start == index:
            index_node = node
            pre_node.next = node.next
            self.length -= 1

    def updateNode(self,index,data):
        if index <0 or  index >= self.length:
            print 'error: out of index'
            return
        start = 0  ##第一个节点位置
        node = self.head
        while node.next and start < index:
            node = node.next
            start += 1
        if start == index:
           node.val = data

    def getItem(self,index):
        if index < 0 or index >= self.length:
            print 'error: out of index'
            return
        start = 0  ##第一个节点位置
        node = self.head
        while node.next and start < index:
            node = node.next
            start += 1
        return node.val

    def getIndex(self,data):
        if self.isEmpty():
            print "this chain table is empty."
            return
        start = 0
        node = self.head
        while node:
            if node.val == data:
                return start
            else:
                node = node.next
                start += 1
        if  start  == self.length:
            print "%s not found" % str(data)
            return

    def insertNode(self,index,data):
        item = None
        if isinstance(item, data):
            item = data
        else:
            item = ListNode(data)

        if index <0 or  index >= self.length:
            print 'error: out of index'
            return

        if  index == 0:
            head = self.head
            self.head = data
            self.head.next = head
            self.length += 1
            return

        else:
            start = 0  ##第一个节点位置
            pre_node = self.head
            next_node = self.head
            while next_node.next and start < index:
                pre_node = next_node
                next_node = pre_node.next
                start += 1
            if start == index:
                pre_node.next = item
                item.next = next_node
                self.length += 1

    def clear(self):
        self.head = None
        self.length = 0




    def generateNonde(self,items1, items2):
        items1_list = []
        items2_list = []
        for i in items1:
            if i in ['0','1','2','3','4','5','6','7','8','9']:
                items1_list.append(int(i))
        for y in items2:
            if y in ['0','1','2','3','4','5','6','7','8','9']:
                items2_list.append(int(y))
        chain1 = Chain()
        chain2 = Chain()
        for i in items1_list:
            chain1.appendNode(i)
        for y in items2_list:
            chain2.appendNode(y)
        return chain1, chain2, chain1.length,chain2.length


class Solution(object):
    def addTwoNumbers(self, l1, l2,length1,length2):
        """
                    :type l1: ListNode
                    :type l2: ListNode
                    :rtype: ListNode
                    """
        list1_str = ''
        list2_str = ''
        chain3 = Chain()

        for i in range(length1, 0, -1):
            list1_str += str(l1.getItem(i - 1))

        for y in range(length2, 0, -1):
            list2_str += str(l2.getItem(y - 1))

        result = int(list1_str) + int(list2_str)
        result = str(result)
        print result, type(result)

        for i in range(len(result), 0, -1):
            chain3.appendNode(int(result[i - 1]))
        return [chain3.getItem(i) for i in range(chain3.length)]



if __name__ == '__main__':
    chain1, chain2, length1,length2 = Chain().generateNonde("[2,4,3]", "[7,7,9]")
    result = Solution().addTwoNumbers(chain1, chain2,length1,length2)
    print result
    # for i in range(result.length):
    #     print result.getItem(i)